As is well known, the front-end springing of motorcycles now usually takes the form of a telescopic front fork, such that each prong of the fork comprises a fork pipe and bottom case, one nesting in the other. The fork pipe and bottom case may contain both compression springs and oil and work telescopically to absorb the jolts caused by the irregularities of the road surface or other obstacles encountered. When the motorcycle incorporating this type of front-wheel suspension is braked, the fork pipes of the front fork inevitably slide down into the bottom cases by inertia. The front fork thus undergoes compression, almost to the fullest extent possible when the vehicle is braked abruptly.
Such compression of the telescopic front fork upon braking is not only unnecessary but hazardous, because the compressed fork is capable of absorbing significantly less energy of shock than usual. Thus, should the front wheel receive a jolt from some obstacle on the road surface during or immediately after abrupt braking, the front fork will transmit nearly the full impact of the jolt to the handlebars and frame of the motorcycle. The driver may then become unable to make proper steering and control of his machine.